1 // SPDX-License-Identifier: GPL-2.0+
6 * Richard Woodruff <r-woodruff2@ti.com>
7 * Syed Moahmmed Khasim <khasim@ti.com>
10 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
11 * Marius Groeger <mgroeger@sysgo.de>
12 * Alex Zuepke <azu@sysgo.de>
15 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
22 #include <asm/arch/cpu.h>
23 #include <asm/arch/clock.h>
24 #include <linux/delay.h>
26 DECLARE_GLOBAL_DATA_PTR;
28 static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
29 static ulong get_timer_masked(void);
32 * Nothing really to do with interrupts, just starts up a counter.
35 #define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
36 #define TIMER_OVERFLOW_VAL 0xffffffff
37 #define TIMER_LOAD_VAL 0
41 /* start the counter ticking up, reload value on overflow */
42 writel(TIMER_LOAD_VAL, &timer_base->tldr);
44 writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
51 * timer without interrupts
53 ulong get_timer(ulong base)
55 return get_timer_masked() - base;
58 /* delay x useconds */
59 void __udelay(unsigned long usec)
61 long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
62 unsigned long now, last = readl(&timer_base->tcrr);
65 now = readl(&timer_base->tcrr);
66 if (last > now) /* count up timer overflow */
67 tmo -= TIMER_OVERFLOW_VAL - last + now + 1;
74 static ulong get_timer_masked(void)
76 /* current tick value */
77 ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
79 if (now >= gd->arch.lastinc) { /* normal mode (non roll) */
80 /* move stamp fordward with absoulte diff ticks */
81 gd->arch.tbl += (now - gd->arch.lastinc);
82 } else { /* we have rollover of incrementer */
83 gd->arch.tbl += ((TIMER_OVERFLOW_VAL / (TIMER_CLOCK /
84 CONFIG_SYS_HZ)) - gd->arch.lastinc) + now;
86 gd->arch.lastinc = now;
91 * This function is derived from PowerPC code (read timebase as long long).
92 * On ARM it just returns the timer value.
94 unsigned long long get_ticks(void)
100 * This function is derived from PowerPC code (timebase clock frequency).
101 * On ARM it returns the number of timer ticks per second.
103 ulong get_tbclk(void)
105 return CONFIG_SYS_HZ;